The clinical complexities of proper diagnosis and assessment of children with ASD, together with federal and state mandates to provide services, present significant challenges to local schools and public service providers. Autism is increasingly conceptualized to encompass a spectrum of disorders rather than a unitary, classically defined developmental disorder. Given the large number of behaviors that define the "autistic spectrum disorders" (ASD) and the variability seen across individual children even within the same diagnostic category, proper identification and assessment requires experienced clinicians and educators. It appears that better identification and broader categorization have contributed to the increasing numbers of children who are being identified with ASD. Standardized diagnostic instruments that have been demonstrated to be reliable and valid are now widely used in ASD research. While comprehensive, valid assessments are essential for educational planning, the direct clinical or educational benefits of diagnostic distinctions within the autism spectrum are a matter of debate. The applicant proposes to evaluate the range of diagnostic distinctions that are present in children who are receiving educational interventions under the autism category. The nature of diagnostic and educational assessments used by service delivery systems for children with autism will be investigated. These data will be used to determine how the broader definition of autism used by schools compares with a diagnosis based on the use of research-based standardized test instruments by experienced professionals. The applicant is requesting a Career Development Award (K23) to obtain the advanced training in services research she needs to address these issues. The applicant's strong background of academic, research, and clinical training in diagnostic and neuropsychological assessment in children, research design and statistics, and autism specific issues will provide an excellent foundation for this work. The proposed training goals, including becoming familiar with statistics and longitudinal techniques used in services research, and obtaining greater knowledge about schools and school-based assessment services, in conjunction with the research plan, will allow the applicant to pursue innovative approaches to implementing research-based diagnostic and assessment methods for children with autism in community settings.